Pipe or tube mill



Jan. 31, 1939; F 'NDLATER 2,145,589

PIPE OR TUBE MILL Filed June 8, 1937 4 Sheets-Sheet l we 2 W f M w N N UN Ev w WM 7% w i Jan. 31, 1939. 5 HNDLATER 2,145,589

PIPE OR TUBE MILL Filed June 8, 1937 {1 Sheets-Sheet 2 [Mei afar: Z 5TEI/EN50N F7NOLF7TEB.

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Jan. 31, 1939. FlNDLATER- 2,145,589

V/PIPE OR TUBE MILL Filed June 8, 1937 4 Sheets-Sheet 3 I I I l I l 1 lnvenior: 5TEVE/v50/v HNDLflTEE,

Patented Jan. 31, 1939 PIPE OR TUBE MILL Stevenson Findlater, McKeesport, Pa., assignor to National Tube Company, a corporation of New Jersey Application June 8, 1937, Serial No. 147,128

3 Claims.

This invention relates to pipe or tube mills and more particularly to the handling of the mandrel employed therein.

In order to maintain a substantial commercial yield from a pipe or tube mill, the work-piece must be completely rolled in a minimum of time. This, of course, requires the rapid withdrawing and repositioning of the mandrel bar. That is to say, after the work-piece has been rolled and is telescoped over the mandrel bar, the latter must be completely withdrawn from within the workpiece which is then removed from the outlet bed of the mill, after which the mandrel bar is returned to its original position.

On very large mills, for instance those which produce work-pieces of twenty inches in diameter, the mandrel bar and mandrel bar carriage weigh over sixteen thousand pounds and are moved into position at the rate of approximately-five hundred feet per minute. When a thin wall work-piece is being produced, the plug on the mandrel bar must be positioned very close to the metal working rolls of the mill, and if permitted to overrun its true position will occasion considerable damage to the metal working rolls and numerous other parts of the mill.

It is among the objects of the present invention to operate a pipe or tube mill in a manner which is not only rapid but which also eliminates damage to the component parts thereof.

Another object is to provide an inexpensive and emcient apparatus which may be installed on pipe or tube mills of existing design to function" ,in the manner previously mentioned.

The foregoing andfurther objects will be apparent after referring to the drawings, in which: Figure 1 is a plan of a conventional pipe or tube mill which employs cone-shaped metalworking rolls.

Figure 2 is a plan of the mill of Figure 1 on a smaller scale and disclosing fragmentarily the outlet bed thereof.

Figure 3 is a view similar to Figure 2 but disclosing some of the elements of the pipe or tube mill in a different position.

I Figure 4 is a view similar to Figure 1 but disclosing a mandrel bar and the mandrel plug carried thereby in the usual over-run position, which' occasions the injurious result previously mentioned.

Figure 5 is a fragmentary plan of a part of the apparatus of the invention.

Figure 6 is a sectional view on the line VI-VI of Figure 7.

L Figure 7 is an enlarged view on the line VII-VII of Figure 5.

Figure 8 is a Wiring diagram. Figures 9, 10, 11, 12 and 13 are details of control switches. Referring more particularly to the drawings, the numerals 2 and 3 designate a pair of cone shaped metal-working rolls toward which there is extended a compression mandrel bar 4 carrying a mandrel plug 5 which is disposed intermedi- 10 ate the metal-working rolls. After a pipe or tube has been completely rolled between the metal-working rolls 2 and 3, and the intermediately disposed mandrel plug 5, and has moved onto the mandrel bar 4, it is removed from the mill by withdrawing the mandrel bar 4 and mandrel plug 5 and translating the pipe or tube by the usual kick-01f arm (not shown), whereupon it is permitted to roll over a conveniently disposed skid-way 6. According to conventional 20 practice, the mandrel bar 4 is suitably attached to a mandrel bar carriage 8 which rides on an elongated frame 9 that forms part of the outlet bed of the mill.

The outlet bed is provided with a pair of sub- 25 mandrel bar carriage 8. Thus, by driving the 30 motor I2, the mandrel bar carriage B, the mandrel bar 4, and the mandrel plug 5 are moved toward a and away from the mill, for the purpose previously mentioned.

Referring to Figure 7, a vertical support I8 is pivoted as at iii to the outlet bed of the pipe or tube mill adjacent the mandrel bar carriage '8 when the latter is in its forward position.

A laterally extending overhead frame M is mounted on the outlet bed of the pipe or tube 40 mill immediate to the rear of the vertical support 18. This laterally extending overhead frame 2| carries a pair of suitably journaled internally threaded sleeves 23 which extend longitudinally over the outlet bed of the mill. Each of these internally threaded sleeves 23 carries a worm gear 24 which is secured thereto. A reversible electric motor 26 is mounted on the laterally extending overhead frame 2| and is connected by means of a suitable coupling 21 to a shaft 28 which extends over -and across the internally threaded sleeves 23. A pair of worms 29 are secured to the shaft 28 and engage the worm gears 24 .on the internally threaded sleeves 23. The motor 26 is provided with a conventional magnetic bralre 30 for a purpose to be later de-. scribed.

In each of the internally threaded sleeves 23 horizontally disposed rotatable shaft 36 which is disposed above the mandrel bar carriage 8 when the latter is in its forward position. This horizontally disposed rotatable shaft 36 has secured thereto a latch 37 having a flattened portion 38 on its extended end. The upper surface of the mandrel bar carriage 8 is provided with an abutment plate 39 having flattened face 40. At one side of the upper end of the-vertical support I8 there is disposed a fluid-actuated cylinder 42, the piston of which is pivotally connected, as at 43, to a crank 44 which is secured to the horizontally disposed rotatable shaft 36..

According to the foregoing construction and arrangement of elements, it will be seen that the deenergization of the fluid-actuated cylinder 42 will permit the lowering by gravity of the latch 31 in such manner as to present its flattened surface 38 for contact with the flattened surface 40 on the abutment plate 39 on the mandrel bar carriage 8. When the latch 3'! is in this position, the reversible electric motor 26 will be enabled to rotate the internally threaded sleeve 23 to move the screws 32 forwardly and, because of the connection of the latter with the vertical support I8 will move the mandrel bar carriage 8, mandrel bar 4 and mandrel plug 5 toward the metal-working rolls 2 and 3 of the mill.

Any suitable and conventional electric wiring supports including control device, are provided for the motor 26 and magnetic brake 30.

In operation, a tube A, which is shown as having previously been pierced, is introduced between the metal-working rolls 2 and 3 for movement over the mandrel plug 5 on the forward end of the mandrel bar 4. The tube A. is moved over the mandrel plug 5 and mandrel bar 4 by the helical advancing action of the metal-working rolls 2 and 3. As soon as the trailing end of the tube A has moved over the mandrel plug 5 and over the mandrel bar 4, the fluid-actuated cylinder 42 is energized to raise the latch 31, and the motor I2 is suitably actuated (automatically or otherwise) to rotate the roller II in such manner as to withdraw the mandrel bar carriage 8 along the elongated frame 9, sufficiently to remove the mandrel bar 4 from the interior of the tube-A and permit the mandrel plug 5 to drop. The usual kick-oil devices (not shown) are then actuated to translate the tube A from the outlet bed of the mill and permit it to roll down the skid-way 6.

After the energization of the fluid-actuated cylinder 42 to raise the latch 31, the magnetic brake 30 and motor 26 are-energized, thus permitting the latter to move the vertical support I8 rearwardly a predetermined short distance from the position it previously occupied. As soon as the vertical support I8 has moved this short predetermined rearward distance, the motor 26 and magnetic brake 30 are deenergized, thereby applying the latter. Next, the motor I2 is energized in a direction which is' reverse to that previously described, to return the mandrel bar carriage 8 to a position which is proximate but short of its initial position. The fluid-actuated cylinder 42 is then deenergized to, lower the latch 31 into contact with the abutment plate 38 on the mandrel bar carriage 8. The magnetic brake 301s then energized; and the motor 26 energized in a direction of rotation which is reverse of that previously described. The motor 26 then, through rotation of the internally threaded sleeves 23, moves the vertical support I8 forwardly toward the metal-working rolls 2 and 3 a distance which is suflicient to restore the man- Referring to Figure 8 of the drawings, I have illustrated one form of electrical circuit which may be utilized to operate the devices of the invention in the manner previously described. In this diagram the numerals I and I02 designate a pair of suitable power lines carrying normal voltage; such as 220 volts. In order to satisfactorily control the operation of the reversible motor 26, it is connected to the power lines I00 and I02 through a manually operable switch I03 by a line I04 and includes in its circuit contacts I05 and I05 and I06 and I06 which are operated by coils I05 and I06, respectively, in a manner to be later described. The series field of the reversible motor 26 is designated in the line I04 at 26. The magnetic brake 30 for the reversible motor 26 is also connected in series in this line I04, whereby it will be energized during the passage of current therethrough.

A line I I0 is connected between the power lines I00 and I02 and includes in its circuit contacts 2 H4 and II6 which form part of limit switches H2, H4 and H6, respectively; together with a coil I06 which operates the contacts I06 and IIIIi of the motor 26. A line I20 is connected to the line IIO between the contact H2 of the limit switch H2 and the power line I00, and to the line IIO between the coil I06 and the power line I02. This line I20 has included in its circuit contacts II2 II4 and II6 ,'which also form part of the limit switches H2, 4 I

and H6, respectively; together with a coil I05 which operates the contacts I05 and I05 of the motor 26. I

As shown in Figure 7, the reversible motor I2 which drives the mandrel bar carriage 8 is connected through a reversing switch I25 to a pair of power lines I26 and I21 which provide current of suitable voltage; such as 220 volts.

Referring to'Figure 9, the limit switch H2 is shown as comprising an operating arm which is spring-biased as at II2 into connection with the contact II2 but operable by contact with the lower part of the mandrel bar carriage 8, while the latter is in its forward position, into connection with the contact IIZ The limit switch H4 is shown as comprising an operating arm secured to the shaft '36 on the upper part of the vertical support I8. The energization of the fluid cylinder 42 will move the operating arm of the limit switch II4 into connection with the contact H4 and the deenergization of the fluid cylinder 42 will permit the latch 31 on the shaft 36 to drop by gravity and move the operating arm into connection with the contact II 4. y

Referring to Figures 11, 12 and 13 of the drawings, the limit switch H6 is shown as comprising a screw I30 which is secured to and rotates with the shaft 28. This screw I30 carries a nut. I32 which is provided with a centrally depending lug which rides in a guideway I33 formed by part of the laterally extending overhead frame 2I. Each side of the nut I32 is provided with a stud I34 which carries a pivotally mounted roller II6. Each of the rollers II6 rides for a limited distance on a longitudinally adjustable contact strip which is mounted on, but suitably insulated from, the laterally extending overhead frame'2l. These contact strips form contacts II6 and [I6 which operate in a manner to be later described. According to the embodiment illustrated, the rollers II6 will, when in extreme positions, connect either the contact III; or the contact-6 and permit a limited range of travel over the nut I32 during which both contacts will be connected in their respective lines.

While the mandrel bar carriage 8 is in its forward position, the contacts H2 and 4 of the limit switches H2 and H4, respectively, are closed, but the nut I32 of the limit switch II6 occupies its extreme inward position on the shaft I80, thereby breaking connection with the contact 6 but continuing connection with the contact H6 Therefore, the operating coil I06 is now deenergized, thereby opening the contacts I06 and '16 of the reversible motor 26. .The coil I85 is at this time deenergized because the contacts II2 and H4 of the limit switches H2 and HE, respectively, are opened. The foregoing position of elements is represented in the diagram of Figure 8 of the drawings.

As soon as the tube A has been completely pierced by the operation of the metal-working rolls 2 and 3 and the mandrel plug 5 on the forward end of the mandrel bar I, the operator of the mill operates a suitable valve to fill the cylinder 42 with fluid under pressure, thereby,

raising the latch 31. The raising of the latch 31 breaks the connection of the limit switch III with its contact I I4 and makes connection with its contact H4 The operator then operates the reversing switch I25 for the reversible motor I2 to drive the same in such manner as to withdraw the mandrel bar carriage 8. This operation of the motor I2 is continued until the mandrel bar carriage 8 is in its "extreme rearward position.

As soon as the mandrel bar carriage 8 begins its rearward movement caused by the operation of, the reversible motor I2, the contact H2 of the limit switch H2 is closed by its operating 5 spring 2. In view of the fact that the limit switches I I4 and I I6 are at this time already connected with their contacts I N and' I I6, respectively, the coil I05 is energized to close the contacts IIJii' and I05 of the motor 26 by the closing of the contact IE2 of the limit switch H2, as

just described.

This connection of the motor 26 energizes, and therefore releases, the magnetic brake 38 andpermits the former to move the vertical support I8 5 rearwardly from the position it previously occupied. The extent of the movement is short and determined by the distance required by the travel of the nut I32 to break the connection of the contact I I6 with its contacting roller 6. The

a breaking of the connection of the limit switch I I6 with the'contact H6 deenergizes the coil I85 thereby opening the contacts I05 and I05 to deenergize the motor 26 and also the magnetic brake 30 which is then applied.

5 The foregoing operation oi-the devices included in the wiring diagram of Figure 8 is entirely independent of the operation of the reversible motor I2 which, as before stated, is operated towithdraw the mandrel bar carriage 8 to its extreme rearward position, either automatically or manually. When the mandrel bar carriage 8 iscompletely withdrawn, the reversible motor I2 is deenergized. The operator then operates the usual kick-off arms (not shown) to translate the tube A from the outlet bed of the mill whereupon it is permitted to roll over the skid-way 6. The operator then restores the kick-01f arms to their initial positions and operates the reversing switch I25 to drive the reversible motor I2 in such manner as to move the mandrel bar carriage 8 to a position which is proximate, but. short ofi, its initial position. The reversible motor I2 is then deenergized. If desired, the operation of thereversible motor I2 may be regulated by suitable limit switches (not shown).

As soon'as the mandrel bar carriage 8 arrives at its proximate initial position, it operates the limit switch I I2 to make connection with the contact H2 and break connection with the contact H2 At this time the latch 3! is either already in its lowermost position, or is then moved into such position by exhausting the fluid from the fluid cylinder 42, whereupbn-it is permitted by gravity to drop. The lowering of the latch, 3'I operates the limit switch IM to make connection with the contact II4 and break connection with the'contact II4 The limit switches II2 and H6 are already in connection with the contacts 2 and H6, respectively, Therefore, the closing of the contact III of the limit switch II I now energizes the coil I66 which closes the contacts I66 and Hi6 of the reversible motor 26. This energizes the motor 26 and also the magnetic brake 36 which is then released. The motor 26 then moves the vertical support I8 forwardly and, through the latch 31, also the mandrel bar carriage 8. As soon as the mandrel bar carriage 8 is restored to its exactly proper initial position, the nowoutwardly traveling nut I32 breaks the connection of the 'limit switch II6 with the contact H6 but continues its connection with the contact H6". The breaking of the connection of the limit switch H6 with the contact IIIS deenergizes the coil I86, thereby opening the contacts I06 and I86 to deenergize the motor 26 and also the magnetic brake 38 which is then applied.

I The entire apparatus is thus set'for another cycle of operation, which is initiated after the passage of a succeeding tube A through the mills In my copending application, Serial No. 147,127, entitled Pipe or tube mill, and filed concurrently herewith, there is disclosed and claimed an apparatus for preventing the direct impact of the mandrel plug with the metal-working rolls of the mills. In said, copending application, at least .one of the metal-working rolls of the mill is withdrawn from its metal-working position before the mandrel plug is moved into its metal-Working position, whereby said mandrel plug cannot make impact against both of said metal-working rolls. That is to say, if the mandrel plug over-runs its metal-working position, it can only make a glancing impact against one of the metal-working rolls. After the mandrel plug has assumed its metalworking position, or an over-run position, the withdrawn metal-working roll is returned to its metal-working position. If desired, both metalworking rolls can, according to said application, be withdrawn prior to the movement of the mandrel plug to its metal-working position, whereby a glancing impact of the mandrel plug against even one of the metal-working rolls is prevented.

While I have shown and described one specific embodiment of my invention, it will be understood that I do not wish to be limited exactly thereto, since various modifications may be made without departing from the scope of my invention, as defined by the following claims.

I claim:

1. A pipe or tube mill comprising, in combination, a plurality of metal-working rolls, a mandrel disposed intermediate said metal-working rolls, releasable means for holding said mandrel in its fixed metal-working position between said metalworking rolls, means for withdrawing said mandrel from said metal-working rolls to permit the removal therefrom of a pipe or tube, means for moving said mandrel to a position adjacent but spaced from its fixed metal-working position, and means for moving said mandrel into said fixed metal-working position at a decreased rate of speed, said last named means being operable only I when said releasable mandrel holding means is in drel disposed intermediate said metal -working I rolls, releasable means for holding said mandrel in its fixed metal-working position between said metal-working rolls, means for withdrawing said mandrel from said metal-working rolls to permit the removal therefrom of a pipe or tube, said mandrel withdrawing means being operable by the release of said releasable mandrel holding means, means for moving said mandrel to a position adjacent but spaced from its fixed metalworking position, and means for moving said mandrel into said fixed metal-working position at a decreased rate of speed, said last named means beingoperable only when said releasable mandrel holding means is in holding position.

3. A pipe or tube mill comprising, in combination, a plurality of metal-working rolls, a mandrel disposed intermediate said metal-working rolls, releasable means for holding said mandrel in its fixed metal-working position between said metal-working'rolls, means for withdrawing said mandrel from said metal-working rolls to permit the removal therefrom of a pipe or tube, means for moving said mandrel to a position adjacent but spaced from its initial position, and means for moving said mandrel into said initial position at a decreased rate of speed, said last named means being operable only when said mandrel is adjacent to but spaced from said metal-working rolls.

STEVENSON FINDLATER. 

